Venetian blind tilt mechanism with cord repositioning feature



Dec. 2 1951 w. J. STUBER ET AL VENETIAN BLIND TILT MECHANISM WITH CORDREPOSITIONING FEATURE Filed Jan. 2, 1951 #160" WJ J Patented Dec. 25,1951 UNITED STATES eATsNT orrlcs VENETIAN BLIND TILT MECHANISM WITH CORDREE-POSITIONING FEATURE Walter J Stuber and John J. Di lenno,Philadelphia, Pa., assignors to Carey-McFall Company, Philadelphia, Pa.,a corporation of Pennsyl- Vania.

Application January 2, 1951,. Serial No. 203,846

4 (Claims.

The'present invention relates tonew and useful improvements in tiltmechanism-for Venetian When. the Venetian blind is in use, the tilt cordinadvertently slips in one direction or the'other over the pulleyuntil,after repeated manipulations'of the blind, the tilt cord is notcentrally located on the. pulley.. Accordingly,: itbecomes necessaryperiodicaly torelocate the tilt cord;

upon the pulley. This may be done either by manually threading the tiltcord about the pulley, a difiicult and tedious operatiomor bydisengaging the gear from the worm wheel so that the latter may berotated freely relative. to the gear segment. forexample; by eliminatingentirely a portion of the teeth on the. gear segment so that in at-leastonelpositi-on the gear and Worm are out of mesh, a construction whichmay jam when the gear is returnedintosengagementwith the worm.

With the foregoing" in, mind, the principal object ofthepresentinvention isto provide a tilt mechanism for Venetian blindsembodying a novel. construction and arrangement of the gear and worm to.permit rotation of the. latter with respectto the gear withoutcompletedisengagement. of the worm. and gear.

Another object of the present invention. is to.

provide. a novel Venetian. blindtilt mechanism of the stated characterwhichv is constructed to permitv the tilt cord to be easily positionedcentrally withrespect' to the pulley without disengaging the worm andthe gear.

A still" further object of'the present invention is to provide a novelVenetian blind tilt mechanism. having the features and. characteristicsset forth which may be manufactured easily and cheaply and which isefficient' and effective in op eration and. use.

These and other objects ofthe. present invention andthe various featuresand details offthe operation and construction thereof are hereinafter vmore fully set forth and describedwith reference to theacompanyingrdrawing, in which:

Fig; 11 isa-fragmentaryside elevational view of the tilt mechanism for aVenetian blind:

Fig; 2 is an end elevational view of the" tilt mechanism of the presentinvention installed in the head casing of a Venetian blind;

Fig. 3 is an enlarged fragmentary elevational view of the tilt mechanismof the present invention in a removed relationship from the Venetianblind.

Fig. 4 is a sectional view taken on line 4*4,

Fig. 3; and

Fig. 5 is a perspective view of the worm wheel segment of the tiltmechanism made in accordance with the present invention.

Referring more particularly to the drawing, reference numeral I0designates generally the head casing for a Venetian blind. The casing I0comprises a base portion II and relatively verti--- cal side wallportions I2 and I3 which terminate at their upper ends in longitudinalchannel's I4 and I5, respectively. These channels I 4 and I 5 asidefromstiffening the head casing It" also serve to secure the variouscomponent parts of the Venetian blind to the head casing.

In accordance with the present invention, the

tilt mechanism designated generally as I6 comprises a cross-frame memberII. In the illustrated embodiment of the invention, the crossframemember I! is formed of a plate 2I having a foot flange 22 resting on andsecured to thebottom panel I I of the head casing It. The plate 2! isalso provided with an upper flange 23 which extends horizontally fromthe upper end thereof and terminates in vertical projections or ears 24.These ears 24' extend into the longitudinal casing channels I4 and I5,respectively, at the upper edges of the front panel I2 and rear panelI3, and impart rigidity to the casing.

The plate 2! has" secured therein arivet or stud 25 on which isrotatably mounted the gear" portion I9 of a'member 20. Forming a part ofthe member 2iland extending outwardly therefrom is a lateral extension26 which terminates in an arm 21 that is disposed in a planeparallel tothe plane of the gear I9 and spaced axially therefrom. A rectangularopening 29 is-provided centrally in the arm 21' and is adaptedto receivethe correspondingly shaped tilt shaft 30 of the Venetian blind.

A worm wheel 18 is secured upon: a shaft-32.

fixedly secured to the outwardly extending end of the shaft 32 is anotched or serrated pulley '34 about which passes, the customary" tiltcord or.: ,,rope- 35. The cord 35' is directed? downwardly through anopening 35 in the bottom panel. I 1* of the head casing l by means ofguides 31 formed as an integral part of the lower plate flange 22.

The gear portion I9 is provided with a plurality of teeth 38 which areadapted to engage the worm 18 so that rotation of the latter, by pullingthe tilt cord 35 in one direction or the other, operates to rotate thegear portion l9 and thereby effect a corresponding rotation of the tiltshaft 38 to vary the angle or tilt of the slats of the blind as desired.

In accordance with the present invention and with reference particularlyto Fig. of the drawing, the teeth 38 are arranged in equally spacedrelation continuously about the circumference of the gear portion 59from one side of the lateral extension 26 to the other side thereof.However, in order to provide for continued intermeshing of the worm andgear at the junction between the latter and the extension 26 so as toprovide, in effect, a continuous series of teeth entirelycircumferentially of the gear portion 19 for engagement with the worml8, there is stamped from the extension 26 a lug portion 39. This lug 39is reversely bent with respect tothe extension 26 so as to overlie thelatter and extend in the direction of the gear 19, and the free end ofthe lug 38 is disposed intermediate the terminal teeth 38 at theopposite sides of the extension 26 in position to mesh with the worm andperform the function of a tooth on the gear l9. The free end portion ofthe lug 39 is resiliently yieldable so that it may be displaced to alimited extent by the application of force of a certain magnitude.

By reason of this construction, when it is deslrable to relocate thetilt cord 35 with respect to the pulley 34, it is only necessary to tiltthe Venetian blind to the appropriate limit tilt position and thencontinue to exert a substantial pull on the short end of the tilt cord.Since the tilt rod and slats of the blind are in a limit tilt positionthey cannot be rotated further and continued pressure of the worm 58against the lug 39 causes the latter to be yieldably displaced radiallyinward with respect to the gear IS in the manner illustrated in Fig, 4of the drawings, thereby permitting the Worm to be forced over the lug39. By forcing the worm over the lug 39 the worm may be rotated relativeto the gear I9 until the tilt cord 35 is properly relocated on thepulley 34.

From the foregoing, it will be observed that the present inventionprovides a novel Venetian blind tilt mechanism embodying a novelconstruction and arrangement of gear and worm to permit rotation of thelatter with respect tothe gear without the disadvantages of completedisengagement of the worm and gear. Furthermore, the present inventionprovides a novel Venetian blind tilt mechanism which is constructed topermit the tilt cord to be easily positioned centrally with respect tothe pulley without disengaging the Worm and gear.

While a certain embodiment of the present invention has been illustratedand described herein, it is not intended to limit the invention to suchdisclosure and changes and modifications may be incorporated andembodied therein within the scope of the following claims:

We claim:

1. In tilt mechanism for a Venetian blind having the usual tilt shaftfor angularly positioning the slats of the blind,-a rotatably mountedworm, a tilt cord connected to said worm for rotation ally actuating thelatter, a gear normally meshed with said Worm and having drivingconnection with said tilt shaft, said gear having teeth and extendingcircumferentially thereof continuously except for a portion of saidcircumference disposed in confronting relation to the worm in the limittilt positions only, and a member disposed between the gearteeth inconfronting relation to the portion of the gear devoid Of teeth andarranged in the limit tilt positions only of the blind normally to meshwith the Worm and function as a tooth of the gear, said member beingdisplaceable in a direction inwardly of the gear so that in said limittilt positions of the blind continued pull exerted on the tilt cordoperates to cause the worm to displace said member and effect rotationof said worm with respect to the gear to reposition the tilt cord.

2. In tilt mechanism for a Venetian blind having the usual tilt shaftfor angularly positioning the slats of the blind, a rotatably mountedworm, a tilt cord connected to said worm for rotationally actuating thelatter, a member including a gear portion normally meshed with said wormand having a lateral extension from a peripheral part of the gearterminating in a portion having driving connection with said tilt shaft,said member gear portion having teeth extending circumferentiallythereof from one side of the said lateral extension to the other sidethereof, and an element disposed between the gear teeth at oppositesides of the extension and arranged in the limit tilt positions only ofthe blind normally to mesh with the worm and function as a tooth of thegear, said element being resiliently displaceable inwardly with respectto the gear so that in said limit tilt positions of the blind continuedpull exerted on the tilt cord operates to cause said Worm to yieldinglydisplace the element and effect rotation of the Worm with respect to thegear to reposition the tilt cord.

3. In tilt mechanism for a Venetian blind having the usual tilt shaftfor angularly positioning the slats of the blind, a rotatably mountedworm, a tilt cord connected to said worm for rotationally actuating thelatter, a member including a gear portion normally meshed with said wormand having a lateral extension from a peripheral part of the gearterminating in a portion having driving connection with said tilt shaft,said member gear portion having teeth extending circumferentiallythereof from one side of the said lateral extension to the other sidethereof, and an element on said lateral extension disposed be tween thegear teeth at opposite sides of the extension and arranged in the limittilt positions only of the blind normally to mesh with the worm andfunction as a tooth of the gear, said element being resilientlydisplaceable inwardly with respect to the gear, so that insaid limittilt positions of the blind continued pull exerted on the tilt cordoperates to cause said worm to yieldingly displace the element andeffect rotation of the worm with respect to the gear to reposition thetilt cord.

4. In tilt mechanism for a Venetian blind having the usual tilt shaftfor angularly positioning the slats of the blind, a rotatably mountedWorm, a tilt cord connected to said worm for rotationally actuating thelatter, a member including a gear portion normally meshed with said Wormand having a lateral extension from .a peripheral part of the gearterminating in a portion having driving connection with said tilt shaft,said member portion having teeth extending circum- 2,580,253 a 5 vi'erentially thereof from one side of the said latexerted on the tiltcord operates to cause said eral extension to the other side thereof,and a worm to yieldingly displace the element and eflug pressed fromsaid lateral extension disposed fect rotation of the worm with respectto the gear between the gear teeth at opposite sides of the toreposition the tilt cord. extension and arranged in the limit tiltposi-j 5 tions only of the blind normally to mesh with WALTER J. STUBER.the worm and function as a tooth of the gear, JOHN m IENNQ, said elementbeing resiliently displaceable in.-

wardly with respect to the gear so that in said No references cited.

limit tilt positions of the blind continued pull 10

